title: Cervical radiographical alignment: comprehensive assessment techniques and potential importance in cervical myelopathy.
abstract: METHODS
  Narrative review.
  
  
  OBJECTIVE
  To provide a comprehensive narrative review of cervical alignment parameters, the methods for quantifying cervical alignment, normal cervical alignment values, and how alignment is associated with cervical deformity and myelopathy with discussions of health-related quality of life.
  
  
  BACKGROUND
  Indications for surgery to correct cervical alignment are not well-defined and there is no set standard to address the amount of correction to be achieved. In addition, classifications of cervical deformity have yet to be fully established and treatment options defined and clarified.
  
  
  METHODS
  A survey of the cervical spine literature was conducted.
  
  
  RESULTS
  New normative cervical alignment values from an asymptomatic volunteer population are introduced, updated methods for quantifying cervical alignment are discussed, and describing the relationship between cervical alignment, disability, and myelopathy are outlined. Specifically, methods used to quantify cervical alignment include cervical lordosis, cervical sagittal vertical axis, and horizontal gaze with the chin-brow vertical angle. Updated methods include T1 slope. Evidence from a few recent studies suggests correlations between radiographical parameters in the cervical spine and health-related quality of life. Analysis of the cervical regional alignment with respect to overall spinal pelvic alignment is emerging and critical. Cervical myelopathy and sagittal alignment of the cervical spine are closely related as cervical deformity can lead to spinal cord compression and tension.
  
  
  CONCLUSIONS
  Cervical deformity correction should take on a comprehensive approach in assessing global cervical-pelvic relationships and the radiographical parameters that effect health-related quality of life scores are not well-defined. Cervical alignment may be important in assessment and treatment of cervical myelopathy. Future work should concentrate on correlation of cervical alignment parameters to disability scores and myelopathy outcomes. SUMMARY STATEMENTS: STATEMENT 1: Cervical sagittal alignment (cervical SVA and kyphosis) is related to thoracolumbar spinal pelvic alignment and to T1 slope. STATEMENT 2: When significant deformity is clinically or radiographically suspected, regional cervical and relative global spinal alignment should be evaluated preoperatively via standing 3-foot scoliosis X-rays for appropriate operative planning. STATEMENT 3: Cervical sagittal alignment (C2-C7 SVA) is correlated to regional disability, general health scores and to myelopathy severity. STATEMENT 4: When performing decompressive surgery for CSM, consideration should be given to correction of cervical kyphosis and cervical sagittal imbalance (C2-C7 SVA) when present.
authors.affiliation: *Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA †Department of Orthopaedic Surgery, NYU Hospital for Joint Diseases, New York, NY ‡Université Aix-Marseille, Marseille, France §University of California, San Diego, School of Medicine, La Jolla, CA ¶Spine Unit 2, Bordeaux University Hospital, Bordeaux, France ‖Division of Neurosurgery, University of Toronto, Toronto, Ontario Canada **Department of Orthopaedic Surgery, Loyola University, Chicago, IL ††Department of Neurosurgery, Rush University, Chicago, IL ‡‡Department of Orthopaedic Surgery, Hospital for Special Surgery, New York, NY; and §§Department of Neurosurgery, University of Virginia Health System, Charlottesville, VA.
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Ames
authors.forename: Benjamin
authors.initials: B
authors.lastname: Blondel
authors.forename: Justin K
authors.initials: JK
authors.lastname: Scheer
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Schwab
authors.forename: Jean-Charles
authors.initials: JC
authors.lastname: Le Huec
authors.forename: Eric M
authors.initials: EM
authors.lastname: Massicotte
authors.forename: Alpesh A
authors.initials: AA
authors.lastname: Patel
authors.forename: Vincent C
authors.initials: VC
authors.lastname: Traynelis
authors.forename: Han Jo
authors.initials: HJ
authors.lastname: Kim
authors.forename: Christopher I
authors.initials: CI
authors.lastname: Shaffrey
authors.forename: Justin S
authors.initials: JS
authors.lastname: Smith
authors.forename: Virginie
authors.initials: V
authors.lastname: Lafage
mesh_terms: D002574:Cervical Vertebrae / Q000000981:diagnostic imaging* / Q000601:surgery; D006801:Humans; D007738:Kyphosis / Q000000981:diagnostic imaging* / Q000601:surgery; D008141:Lordosis / Q000000981:diagnostic imaging* / Q000601:surgery; D008953:Models, Anatomic; D011788:Quality of Life; D011859:Radiography; D013118:Spinal Cord Diseases / Q000000981:diagnostic imaging* / Q000601:surgery; D016896:Treatment Outcome